I got caught by my girlfriend masturbating?

I was in Church the other day and the priest was talking, I was checking out this hot girl in the pew in front of me. I opened my pants and started masturbating but I tried to not let anyone see. I saw the bishop look at me a little weird so I think he might've seen me. I eventually finished, then they started passing out the bread and grape juice stuff. I forgot to button up my pants though, I stood up to grab the cracker and my pants dropped. I turned around to pick them up and my girlfriend sitting next to me noticed the huge stain on my underwear and got this offended look on her face then ran out. She's a serious catholic for some reason, I don't really care about that stuff but she's really into it. I'm embarrassed now, what do I do?